Gotschlich E C, Seiff M, Blake M S
J Exp Med. 1987 Feb 1;165(2):471-82. doi: 10.1084/jem.165.2.471.
The insert of a lambda gt11 clone expressing gonococcal protein III was sequenced. The deduced amino acid sequence showed a coding frame of 236 amino acids with a typical 22-amino-acid signal peptide, followed by the known NH2-terminal sequence of PIII. The mature protein has a molecular weight of 23,298. It was found that PIII had extensive and very striking homology to the carboxy-terminal portion of enterobacterial OmpA proteins. The homology encompasses the OmpA domain that is believed to be located in the periplasmic space. If the disposition of PIII across the OM is analogous, then the surface-exposed domain consists of less than 40 amino acids. These include a potential 15-amino-acid disulfide loop, a feature not found in OmpA proteins. Hybridization studies with the sequenced insert indicated that it contained a repetitive sequence that occurred at least 20 times in the genome. By additional hybridization studies the area containing the repetitive sequence was narrowed to a region of 43 bp. This region contained an exact copy of the consensus sequence of a 26-bp repetitive sequence recently described. An analogous sequence recurs in an inverted orientation 53 bp downstream.
对一个表达淋球菌蛋白III的λgt11克隆的插入片段进行了测序。推导的氨基酸序列显示有一个236个氨基酸的编码框，带有一个典型的22个氨基酸的信号肽，其后是已知的PIII的NH2末端序列。成熟蛋白的分子量为23,298。发现PIII与肠杆菌OmpA蛋白的羧基末端部分有广泛且非常显著的同源性。这种同源性涵盖了据信位于周质空间的OmpA结构域。如果PIII跨外膜的排布类似，那么表面暴露结构域由少于40个氨基酸组成。这些氨基酸包括一个潜在的15个氨基酸的二硫键环，这是在OmpA蛋白中未发现的一个特征。用测序的插入片段进行的杂交研究表明，它含有一个在基因组中至少出现20次的重复序列。通过进一步的杂交研究，包含重复序列的区域被缩小到一个43 bp的区域。该区域包含最近描述的一个26 bp重复序列的共有序列的精确拷贝。一个类似序列在下游53 bp处以反向重复出现。
